For various medical reasons, such as diagnostic tests or the determination of suitability as a tissue donor, it is often necessary for a physician to obtain a sample of a patient's body tissue. In particular, bone marrow is frequently retrieved for later pathological study as described in U.S. Pat. No. 5,634,473, the entirety of which is hereby incorporated by reference as if set forth herein. The U.S. Pat. No. '473 discloses a biopsy needle assembly which includes a snare that operates to sever and/or retain a sample. The snare is coupled to the cannula with radially directed coupling elements. The radially directed coupling elements include a radially projecting tab which is received within an aperture formed in a sidewall of the cannula.